Design and Analysis of a Multilayer Meander Line Circular Polarization Selective Structure

摘要

We present a nonresonant circular polarization selective structure (CPSS) based on multiple layers of stacked meander line sheets arranged closely after each other. The structure has a total thickness of 13.5 mm (0.68 wavelengths at center frequency 15 GHz) and is realized by cascading printed circuit boards interspaced with a low-permittivity foam material, and the different layers are bonded together with thin layers of adhesive spray. A design procedure is presented that can be used to optimize the proposed structure based on its target band of operation. Based on this method, an optimized design has been simulated, and the structure shows a return loss and an insertion loss better than 0.5 dB, and axial ratio in transmission and reflection better than 0.78 dB, over a fractional bandwidth of 45.8% at normal incidence, fully covering the K-band 12–18 GHz. The functionality of the structure has been verified experimentally through measurements, both in reflection and transmission, with a total bandwidth of 42.0%, covering 86.7% of the K band. The simulated performance at oblique angles of incidence shows significant improvements when compared to classical resonant CPSSs.